APPARATUS FOR DISINTEGRATION OF WASTE, IN PARTICULAR GARDEN REFUSE

Abstract: By an apparatus for disintegration of waste, in particular garden refuse, or so-called compost mill (2), comprising a tubular inlet funnel (8) for material to be disintegrated, a cutting device (10), a material outlet (15) and a drive engine (14), the cutting device (10) comprises a drum (12) with an external, worm-shaped projection, which forms a combined material conveyor part (20) and cutting part (16), and a stationary cutting edge (18), and where the drum (12) is drive-connected with an electric engine (14) preferably via a gear, as the drum (12) is adapted to be rotated with a speed of 300 to 500 rpm, preferably about 400 rpm. The drum (12) is either inclined in relation to the inlet funnel or it is secured around a mainly horizontal axle, and the external worm-shaped projection of the drum has a bigger pitch at the rearmost part, which forms the material conveyor part (20), than the pitch of the frontmost part, which forms the cutting part (16), which is provided with a sharp edge at the side facing the cutting edge (18).

Description: Apparatus for disintegration of waste, in particular garden refuse The present invention relates to an apparatus for disintegration of waste, in particular garden refuse, or so-called compost mill of the type described in the introductory part of claim 1. More specifically, the invention relates to a disintegration apparatus or a compost mill of said type - preferably for hobby use. Minor aggregates of this type comprise most often an electric drive engine. To obtain the optimum use of the garden refuse it has become very popular among private garden owners to use compost mills, which in particular give problems in relation to the neighbours, as the electric driven compost mills are known as very noisy, which especially is caused by the mechanical consturcti- on of the cutting aggegate; but also the high speed of the driving electric motor is a contributury cause to relative noise nuisance, because the cutting aggregate normally is directly coupled to the electric engivne, that is being rotated with a high speed. Known compost mills often have problems with the capacity, which mostly is due to a bad utilization of the engine effect and a technical insufficient cutting or knife system with plate-shaped knives, which in practice often cause that compost mills are relatively easy to choke for instance by filling too thick branch material into the mill. The invention has for its purpose to provide an apparatus for disintegration of waste, in particular garden refuse of the type described in the introductory part, and which by means of simple provisions makes it possible - without specific noise nuisances - to obtain a quick and effective disintegration of garden refuse - including relatively heavy branches. The apparatus for disintegration or the compost mill according to the invention is distinctive in that the cutting device comprises a drum with an external, worm-shaped projection, which forms a combined material conveyor and cutting part, and a stationary cutting edge, and that the drum is drive-connected with a preferably electric engine via a gear, as the drum is adapted to be rotated with a speed of 300 to 500 rpm, preferably about 400 rpm. By means of simple provisions it hereby becomes possible to obtain a both effective and silence compost mill, and which in spite of the very modest speed still have great forces and big capacity. Appropriately the compost mills according to the invention is such provided, that the position of the drum is inclined in relation to the inlet funnel, that said worm-shaped projection of the drum has a bigger pitch at the rearmost part, which forms the material conveyor part, than the pitch of the frontmost part, which forms the cutting part, and that the worm-shaped cutting part at the side facing the cutting edge is provided with a sharp edge. In order to optimize the cutting system of the compost mills said cutting edge may advantageously be such provided, that it partly surrounds the cutting part of the drum and partly is stretching external in an acute angle inwards around the drum along the cutting part, that is that the cutting edge is stretching arched both in the axial direction of the drum and in said acute angle thereto. An preferably the cutting edge - in order to maintain its sharpness - is made from a relatively soft material, for instance non-hardened steel, and is arranged in such a self- sharpening and displacable manner, that the cutting edge, for instance by means of an external eccentric, may be pressed against the worm-shaped cutting part of the drum. To easy the exchange of the worm-shaped cutting part it is apparently provided as a separate drum part, which is adapted to be inserted over and secured to a frontmost narrow end part of the cutting device of said drum. In addition to that it may be advantagously that that part of the cutting part, which by co-operation with the cutting edge actively assist in the cutting over of the material, is produced of specially hardened knife steel. In order to simplify the reduction of the speed the cutting device of the drum at the rearmost end, that is opposite the cutting edge, is provided with an internal, peripheral toothed rim. if the drum is blocked by material, it may be appopriate that the apparatus is such provided that the preferable electric drive engine is provided with a control system being adapted to reverse the drive engine briefly, or that the gear is provided with a control mechanism being adapted to reverse the drum briefly. The invention is explained in more detail in the following with reference to the drawing, in which:- Fig. 1 shows a side view - partly in section - of an embodiment for a compost mill according to the invention, Fig. 2 shows an end view - partly in section - of the composst mill shown in Fig. 1, Fig. 3 shows an enlarged sectional detail view cf. the circle in Fig. 1 of a worm- shaped cutting edge for a compost mill according to the invention, Fig. 4 shows a sectional side view of a preferred embodiment for the combined transport and cutting drum for a compost mill according to the invention, Figs. 5-7 show situation views of the cutting system for a compost mill according to the invention, Fig. 8 shows a side view - partly in sections - of a preferred embodiment of a compost mill according to the invention, and Fig. 9 shows an end view of the compost mill cf. Fig. 8. The compost mill 2 shown in Figs. 1 and 2 comprises an apparatus frame 4 with drive wheels 6, a tubular inlet funnel 8, a cutting aggregate 10 with a combined transport and cutting drum 12 and an electric drive engine 14. The combined transport and cutting drum 12 is shown in more details in Fig. 4, while a engagement area between a worm-shaped cutting device 16 and a stationary cutting edge 18 cf. the circle of Fig. 1 is shown enlarged in Fig. 3. An external also worm- shaped transport part 20 of the drum 12 continues into the worm-shaped cutting device 16. The transport part 20 has - as shown - larger pitch than that of the cutting device 16, so that the material, which is to be disintegrated, for instance a branch 22 (Figs. 5-7), quickly is conveyed to the cutting device 16. In order to make the cutting function itself more effective, the cutting device 16 has smaller pitch than that of the transport part 20. As shown most clearly in Fig. 4 the cutting device 16 is provided in a short, separate drum part 24, which is inserted around a narrow end part 26 of the drum 12 and secured thereto, for instance by means of radial screws 28. Opposite the cutting device 16 the drum 12 is provided with an internal toothed rim 30, in which a toothed drive wheel 32, which is secured to a journal 34 of the drive engine 14, engages. In fig. 3 is shown how the cutting edge 18, which is stretching half circular both in the axial direction of the drum and perpendicular thereto, is arranged in a displacable manner, so that the cutting edge in an alsol self-sharpening manner - by means of an eccentric 36 - may be lead downwards to engagement with the cutting device 16. The cutting edge 18 is made from a relatively soft material, for instance aluminium, so that the cutting device 16 may be allowed to "adjust" the cutting edge 18, when the latter is displaced a little towards the cutting device 16. A preferred embodiment for compost mill 38 according to the invention is shown in Figs. 8 and 9, where the combined transport and cutting drum 12 is arranged inclined in relation to the also inclined inlet funnel 8, that is that the cutting edge 18, which is placed inside the inlet funnel 8, forms an acute angle (about 50°) in relation to the transport and cutting drum 12. Hereby a more effective material transport is obtained towards the active cutting engagement between the cutting device 16 and the cutting edge 18, and the neccessary cutting power may be reduced. On the lower end of the cutting drum 12 a discharge wing 40 is placed, which currently lead the grinded material from a cavity 41 under cutting drum 12 out in the material discharge 42, which by this embodiment consists of a tube with rectangular cross section. Experiments have shown, that the compost mill according to the invention has a so far exceptionally low noise level of about 66 dBA at idle run and about 80 dBA during use. The main aspect of the invention - to provide a both effective and silent compost mill - may primarily be obtained by use of an electric drive engine; but it will - in relation to the the effectiveness of the cutting function - be within the scope of the invention alternatively to use a combustion engine for driving the compost mill according to the invention, so that the latter also advantageously may be used in more remote locations. A further alternative may be, that a compost mill according to the invention - possible with an enlarged cutting drum - could be built on a tractor and be driven either by the power take-off of the tractor or by a hydraulic engine.

Claims: CLAIMS: 1. An apparatus for disintegration of waste, in particular garden refuse, or so-called compost mill, comprising a tubular inlet funnel for material to be disintegrated, a cutting device, a material outlet and a drive engine, characterized in that the cutting device comprises a drum with an external, worm-shaped projection, which forms a combined material conveyor and cutting part, and a stationary cutting edge, and that the drum is drive-connected with a preferably electric engine via a gear, as the drum is adapted to be rotated with a speed of 300 to 500 rpm, preferably about 400 rpm. 2. An apparatus according to claim ^characterized in that the position of the drum is inclined in relation to the inlet funnel, that said worm-shaped projection of the drum has a bigger pitch at the rearmost part, which forms the material conveyor part, than the pitch of the frontmost part, which forms the cutting part, and that the worm- shaped cutting part at the side facing the cutting edge is provided with a sharp edge. 3. An apparatus according to claim 1, characterized in that said cutting edge is such provided, that it partly surrounds the cutting part of the drum and partly is stret¬ ching external in an acute angle inwards around the drum along the cutting part, that is that the cutting edge is stretching arched both in the axial direction of the drum and in said acute angle thereto. 4. An apparatus according to claim 3, characterized in that the cutting edge is made from a relatively soft material, for instance non-hardened steel, and is arranged in such a self-sharpening and displacable manner, that the cutting edge, for instance by means of an external eccentric, may be pressed against the worm-shaped cutting part of the drum. 5. An apparatus according to claim 1, characterized in the worm-shaped cutting part is provided as a separate drum part, which is adapted to be inserted over and secured to a frontmost narrow end part of the cutting device of said drum. 6. An apparatus according to claims 1 -3, characterized in that the cutting device of the drum at the rearmost end, that is opposite the cutting edge, is provided with an internal, peripheral toothed rim, which is directly drive-connected with a pinion mounted on the journal of said electric engine. 7. An apparatus according to claim 1, characterized in that the preferable electric drive engine is provided with a control system being adapted to reverse the drive engine briefly, or that the gear is provided with a control mechanism being adapted to reverse the drum briefly.

Inventors: FRANDSEN KARL JOHAN KLITGAARD, FRANDSEN, KARL, JOHAN, KLITGAARD
Applicants: BALLERMANN KARIN, FRANDSEN KARL JOHAN KLITGAARD, BALLERMANN, KARIN, FRANDSEN, KARL, JOHAN, KLITGAARD
Application year: 1994
Main classification: B02C18
IPC codes: B02C18, B02C19